This application relates to a shroud for a variable vane structure in a gas turbine engine, wherein the shroud is formed of two components connected together by a threaded fastener extending into a blind hole in one of the two components.
Gas turbine engines are known, and have a plurality of sections. Typically, a compressor section receives air and compresses that air. The air is delivered downstream to a combustor, and is mixed with fuel. The air and fuel is combusted, and the products of combustion are passed downstream over turbine rotors. The turbine rotors are driven to rotate.
The compressor section typically includes a plurality of rotor stages and intermediate stationary vane stages. The rotor stages each include a plurality of blades which have airfoils to receive and compress air, and deliver that air downstream. Intermediate each stage of rotor blades are stationary vanes. Under certain conditions it is desirable to redirect the airflow between the compression stages. Thus, the vanes have a variable profile, and may be caused to rotate on a pivot axis to control the direction of air from one compression stage as it approaches the next compression stage.
Such variable vanes are mounted in inner and outer shrouds. In the prior art, at least some of these shrouds have been formed of at least two separate components which meet along a flat mating surface at the pivot axis of the vane. This prior art structure has included a hole extending through both components. A threaded fastener, such as a bolt, extends through the hole, and a nut is secured at an opposed end of the hole. This structure requires a relatively great radial profile for the shroud, due to the nut.